Some wireless communication systems may communicate over the Millimeter wave (mmWave) frequency band, e.g., the 60 GHz Frequency band. A mmWave propagation has a few major distinctive features in comparison with lower frequency bands, e.g., the frequency bands of 2.4-5 GHz. For example, the mmWave propagation may have a propagation loss greater than the propagation loss in the lower frequency bands, and may have Quasi-optical propagation properties.
A mmWave communication system may use high-gain directional antennas to compensate for large path loss and/or employ beam-steering techniques. Design of appropriate antenna system and/or further signal processing may be an important aspect of mmWave communication system development.
Some wireless communication systems use multi-element phased antenna arrays for creation of a directional antenna pattern. A phased antenna array may form a directive antenna pattern or a beam, which may be steered by setting appropriate signal phases at the antenna elements.
Beamforming combines elements in a phased array in such a way that signals at particular angles experience constructive interference while others experience destructive interference. Using the beamforming, different wireless devices can exchange data via different communication channels with different subarrays of antennas. Different communication channels may have different performance metric. Accordingly, the proper assignment of different communication channels to communication among different wireless devices can increase the overall performance of wireless communication.
Currently, the assignment of different communication channels is performed using Hungarian method that iteratively tests all possible combinations of assignments to select a combination with the best total award, e.g., the best total single-to-noise ratio. The Hungarian approach creates a tree of possible combinations, each path from a root node to a leaf node includes an equal number of nodes, each node represents an assignment, i.e., each path is a combination of assignments. See, e.g., a patent document U.S. Pat. No. 9,001,879.
The Hungarian method is a combinatorial optimization that solves the assignment problem in polynomial time. However, as a number of wireless communication devices increases, the optimization bounded by the polynomial time may be inadequate for some real-time wireless communications.